For the case of () we have the following result. Below we cite [1]} and it should be noted that the notation of that article differs slightly to this one,
so we mean of course that the equation holds in the notation of this article. Also note that we use the inverse of \(p_{t}^{N}\) , but as noted above this need not be the case and then
the constraint on \(N\)  below is not required.
